The POWER statement performs power and sample size analyses for the Type III F tests that are specified in the MTEST= option, for each effect in the model that is defined by the MODEL statement, and for the contrasts that are defined by all CONTRAST , MANOVA , and REPEATED statements. The POWER statement must appear after the MODEL statement if the EFFECTS= option is used in the POWER statement.
For information about the power and sample size computational methods and formulas, see the section Computational Methods and Formulas.
Table 47.5 summarizes the options available in the POWER statement.
Table 47.5: POWER Statement Options
Option 
Description 

Specify test statistic 

Specifies the test statistic for a multivariate model 

Specifies the form of the HuynhFeldt epsilon for MTEST=HF 

Specify analysis information 

Specifies the level of significance of each test 

Specifies the model effects 

Specify covariates for a univariate model 

Specifies multiple correlation () between covariates and response 

Specifies additional degrees of freedom due to covariates 

Specifies proportional variance reduction (r) due to covariates 

Specify variability 

Specifies the correlation matrix of the dependent variables in a multivariate model 

Specifies the correlations among the dependent variables in a multivariate model 

Specifies the covariance matrix of the dependent variables in a multivariate model 

Defines a matrix or vector 

Specifies the vector of error standard deviations for each dependent variable in a multivariate model 

Specifies the common error standard deviation 

Specify sample size 

Enables fractional input and output for sample sizes 

Specifies the sample size 

Specify power 

Specifies power 

Choose computational method 

Specifies the computational method for multivariate tests 

Control ordering in output 

Specifies the location of the Dependent or Transformation column in the output 

Controls ordering in output 
Table 47.6 summarizes the valid result parameters.
Table 47.6: Summary of Result Parameters in the POWER Statement
Solve for 
Syntax 

Power 
POWER = . 
Sample size 
NTOTAL = . 
To specify the variability in a multivariate model, choose one of the following parameterizations:
standard deviations and correlations (using the MATRIX= , SQRTVAR= , and CORRS= options)
common standard deviation and correlations (using the STDDEV= , MATRIX= , and CORRS= options)
standard deviations and correlation matrix (using the MATRIX= , SQRTVAR= , and CORRMAT= options)
common standard deviation and correlation matrix (using the STDDEV= , MATRIX= , and CORRMAT= options)
For the relationship between covariates and response in a univariate model, specify either the multiple correlation (by using the CORRXY= option) or the proportional reduction in total R square (by using the PROPVARREDUCTION= option).